Merge tag 'x86_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 fixes from Borislav Petkov:

 - Have the Automatic IBRS setting check on AMD does not falsely fire in
   the guest when it has been set already on the host

 - Make sure cacheinfo structures memory is allocated to address a boot
   NULL ptr dereference on Intel Meteor Lake which has different numbers
   of subleafs in its CPUID(4) leaf

 - Take care of the GDT restoring on the kexec path too, as expected by
   the kernel

 - Make sure SMP is not disabled when IO-APIC is disabled on the kernel
   cmdline

 - Add a PGD flag _PAGE_NOPTISHADOW to instruct machinery not to
   propagate changes to the kernelmode page tables, to the user portion,
   in PTI

 - Mark Intel Lunar Lake as affected by an issue where MONITOR wakeups
   can get lost and thus user-visible delays happen

 - Make sure PKRU is properly restored with XRSTOR on AMD after a PRKU
   write of 0 (WRPKRU) which will mark PKRU in its init state and thus
   lose the actual buffer

* tag 'x86_urgent_for_v6.13_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/CPU/AMD: WARN when setting EFER.AUTOIBRS if and only if the WRMSR fails
  x86/cacheinfo: Delete global num_cache_leaves
  cacheinfo: Allocate memory during CPU hotplug if not done from the primary CPU
  x86/kexec: Restore GDT on return from ::preserve_context kexec
  x86/cpu/topology: Remove limit of CPUs due to disabled IO/APIC
  x86/mm: Add _PAGE_NOPTISHADOW bit to avoid updating userspace page tables
  x86/cpu: Add Lunar Lake to list of CPUs with a broken MONITOR implementation
  x86/pkeys: Ensure updated PKRU value is XRSTOR'd
  x86/pkeys: Change caller of update_pkru_in_sigframe()

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index 609935ad5091..cf0d455209d7 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -58,7 +58,7 @@ bool last_level_cache_is_valid(unsigned int cpu)
 {
 	struct cacheinfo *llc;
 
-	if (!cache_leaves(cpu))
+	if (!cache_leaves(cpu) || !per_cpu_cacheinfo(cpu))
 		return false;
 
 	llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
@@ -458,11 +458,9 @@ int __weak populate_cache_leaves(unsigned int cpu)
 	return -ENOENT;
 }
 
-static inline
-int allocate_cache_info(int cpu)
+static inline int allocate_cache_info(int cpu)
 {
-	per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu),
-					 sizeof(struct cacheinfo), GFP_ATOMIC);
+	per_cpu_cacheinfo(cpu) = kcalloc(cache_leaves(cpu), sizeof(struct cacheinfo), GFP_ATOMIC);
 	if (!per_cpu_cacheinfo(cpu)) {
 		cache_leaves(cpu) = 0;
 		return -ENOMEM;
@@ -534,7 +532,11 @@ static inline int init_level_allocate_ci(unsigned int cpu)
 	 */
 	ci_cacheinfo(cpu)->early_ci_levels = false;
 
-	if (cache_leaves(cpu) <= early_leaves)
+	/*
+	 * Some architectures (e.g., x86) do not use early initialization.
+	 * Allocate memory now in such case.
+	 */
+	if (cache_leaves(cpu) <= early_leaves && per_cpu_cacheinfo(cpu))
 		return 0;
 
 	kfree(per_cpu_cacheinfo(cpu));